This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The objective of this work is to explore techniques for improvements in imaging cancer with genetically encoded magnetite using magnetic resonance imaging. Magnetotactic bacteria AMB-1 produce magnetite particles and colonize tumors in mice following systemic delivery [1]. Several techniques exist for visualization of the magnetite particles, but accurate quantitation in vivo remains challenging. In this work, two methods were implemented for positive contrast imaging and quantitative detection of the magnetite particles on the 7T animal scanner.